Method and system for measuring physical quantities

Abstract

To provide a technique that can accurately measure the physical quantity of a belt-like object, which is a measurement target, even when the position or inclination of the belt-like object is changed.SOLUTION: A physical quantity measurement method is to measure the physical quantity of a belt-like object with a measurement device while continuously conveying the belt-like object, and includes: a first step of determining the amount of displacement and the amount inclination from a reference surface around a measurement point of the belt-like object; and a second step of correcting the position and angle of the measurement device from the determined amount of displacement and amount of inclination.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a physical quantity measurement method and a physical quantity measurement system for measuring a physical quantity on a surface of a conveyed belt-shaped object. [Background Art]

[0002] In the material industry, measurement technology for product management is extremely important for maintaining stable quality. Particularly in fields such as iron and steel, non-ferrous metals, papermaking, and resin, where coil-shaped products are produced by winding belt-shaped elongated raw materials, it is necessary to ensure uniform quality regardless of whether it is in the width direction or the longitudinal direction. In a production line for belt-shaped raw materials, it is common that a material being processed is wrapped around a plurality of rolls to be conveyed, the product is further processed, and finally the processed product is wound into a coil shape.

[0003] In such a production line, by installing a sensor (measuring device) at a fixed position in the width direction and performing measurement in accordance with the conveyance of the material, the distribution of the product in the longitudinal direction (conveyance direction) can be measured under relatively stable conditions. On the other hand, when it is intended to increase the number of measurement points and measure the distribution in the width direction, it is necessary to arrange a plurality of sensors in parallel or actively scan the measurement points.

[0004] For example, in an annealing line for thin steel sheets, which is one of the iron and steel processes, temperature control in the manufacturing process for product quality control is important. While information on the temperature distribution in the longitudinal direction of the product is obtained by always measuring one point at the center in the width direction using a radiation thermometer, it is necessary to measure and manage the temperature distribution in the width direction by actively scanning measurement points using a scanning radiation thermometer or the like.

[0005] Measuring distributions in the width direction often involves greater disturbances compared to the longitudinal direction, requiring measures to ensure uniform measurement conditions. For example, in eddy current testing equipment that detects defects on the surface of steel plates using eddy currents, the distance between the sensor head and the target (lift-off) is extremely important. Therefore, if the shape or position of the product changes due to warping or fluttering in the width direction during transport, it becomes a disturbance and degrades performance. To address this, when applying the equipment to steel plates during transport, it is always installed on the part that is wrapped around the roll to suppress fluctuations in warping and fluttering and maintain a uniform lift-off.

[0006] However, some measuring instruments cannot be installed at the roll winding position due to installation constraints. One example is the temperature measurement technology used in the manufacturing line of hot-dip galvanized steel sheets, where zinc is attached to the surface of the base metal in a zinc pod, and then heated using an IH heater or similar during the vertical transport process to alloy it. In the alloying process, the steel sheet is transported vertically for more than 50m without being wound onto a roll until the alloying between the zinc attached to the surface of the product and the base metal has progressed. As a result, disturbances such as warping and fluttering occur in the steel sheet, and these disturbances are particularly noticeable at the edges in the width direction. Despite alloying being such a disturbance-filled process, measurement of the temperature distribution in the width direction is required from the perspective of uniformizing material properties (strength, toughness) and suppressing uneven alloying. If conventional radiation thermometers with fixed emissivity are used to measure such temperature distributions, the emissivity fluctuates greatly depending on the degree of alloying progress, resulting in large temperature measurement errors.

[0007] For this reason, Patent Document 1 proposes a technique for correcting emissivity using two types of reflection. Figure 7 shows a hot-dip galvanizing line to which the technique of Patent Document 1 is applied (corresponding to Figure 4 of Patent Document 1). As shown in Figure 7, in the hot-dip galvanizing line, molten zinc is applied to the steel plate S in a molten zinc pot 11, then heated to the alloying target temperature in a heating furnace 12, and then kept warm in a heat retention tank 13. A temperature measuring device 10 is installed on the entrance side of the heat retention tank 13. The temperature measuring device 10 includes a radiation thermometer 4, a specular reflection light source 5, and a diffuse reflection light source 6. 7 is a shutter. The calculation device 8 acquires the amount of radiant light from the surface of the steel plate S using the radiation thermometer 4, irradiates the steel plate S with light from the specular reflection light source 5 to acquire specular reflected light, irradiates the steel plate S with light from the diffuse reflection light source 6 to acquire diffuse reflected light, and corrects the emissivity using these two types of reflected light.

[0008] However, with the technology described in Patent Document 1, the reflectance cannot be measured correctly if the position or inclination between the thermometer body and the object changes. Measurement errors in reflectance lead to emissivity estimation errors, and ultimately the temperature measurement error also increases. Therefore, it is necessary to stabilize the transport position (pass line) of the object and measure the reflectance under the same conditions, but due to concerns such as zinc adhesion, it is difficult to install the roll and stabilize the pass line by winding.

[0009] On the other hand, Patent Document 2 proposes a method in which a laser is scanned and irradiated onto an object, the tilt of the object is calculated from the position of the maximum brightness of the reflected light, and the maximum reflected brightness is corrected according to the calculated tilt using a predetermined calibration curve. However, the method described in Patent Document 2 can only be used for measurement methods that utilize the maximum brightness of the laser reflection, and its applicability is very limited. It also has the disadvantage of causing lag because the laser is scanned. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 7276515 [Patent Document 2] Patent No. 2733416 [Overview of the project] [Problems that the invention aims to solve]

[0011] As described above, the technology described in Patent Document 1 has the problem that if the position or tilt of the object changes, the reflectivity changes, leading to a large temperature measurement error. Furthermore, the technology described in Patent Document 2 has very limited applicability and also introduces a lag for scanning the laser, making it practically difficult to apply.

[0012] Therefore, the present invention provides a technology that enables accurate measurement of physical quantities of a strip-shaped object even when its position or inclination changes. [Means for solving the problem]

[0013] To solve the above problems, the present invention provides the following [1] to

[10] .

[0014] [1] A method for measuring physical quantities of a strip-shaped object by measuring a measuring device while the strip-shaped object is being continuously transported, The first step is to determine the amount of displacement and inclination from the reference plane around the measurement point of the strip-shaped object, A second step involves correcting the position and angle of the measuring device based on the obtained displacement and tilt amounts, A method for measuring physical quantities, comprising the characteristics of a physical quantity.

[0015] [2] The first step is to obtain the amount of displacement and the amount of inclination from the reference plane by measuring the shape profile of the surface of the strip-shaped object using a two-dimensional laser distance meter, as described in [1].

[0016] [3] The physical quantity measurement method according to [1], wherein the first step uses two or more spot laser rangefinders to measure displacement at two or more points in the width direction of the belt-shaped object such that the measurement point of the belt-shaped object is interposed therebetween, and acquires the displacement amount and the inclination amount from the reference surface.

[0017] [4] The physical quantity measurement method according to any one of [1] to [3], wherein a plurality of the measurement points are provided in the width direction of the belt-shaped object so as to obtain a distribution of the physical quantity in the width direction of the belt-shaped object, and the first step and the second step are performed for each of the plurality of measurement points while scanning the measurement device in the width direction of the belt-shaped object.

[0018] [5] The physical quantity measurement method according to any one of [1] to [3], wherein the measurement device comprises: means for acquiring a radiant light amount at the measurement point of the belt-shaped object; a regular reflection light source that irradiates light onto the surface of the belt-shaped object under regular reflection conditions; and a diffuse reflection light source that irradiates light onto the surface of the belt-shaped object under diffuse reflection conditions; the means for acquiring the radiant light amount is used to acquire a regular reflection light amount when the regular reflection light source irradiates light onto the surface of the belt-shaped object under regular reflection conditions, and a diffuse reflection light amount when the diffuse reflection light source irradiates light onto the surface of the belt-shaped object under diffuse reflection conditions; the relationship between the emissivity, regular reflectance and diffuse reflectance of the surface of the belt-shaped object is modeled, and the emissivity at the measurement point of the belt-shaped object is calculated using the model, the regular reflection light amount and the diffuse reflection light amount.

[0019] [6] A physical quantity measurement system for measuring a physical quantity of a belt-shaped object while continuously conveying the belt-shaped object, comprising: a measurement device that measures a physical quantity of the belt-shaped object; a distance measurement device that measures a distance around a measurement point of the belt-shaped object; an arithmetic device that calculates a displacement amount and an inclination amount from a reference plane around the measurement point of the belt-shaped object from measurement values obtained by the distance measurement device, and outputs a correction signal for correcting the position and angle of the measurement device based on the calculated displacement amount and inclination amount; A physical quantity measurement system comprising the above.

[0020] [7] The physical quantity measurement system according to [6], wherein said distance measuring device comprises a two-dimensional laser rangefinder, measures the shape profile of the surface of said strip-shaped object by means of said two-dimensional laser rangefinder, and acquires said displacement amount and said inclination amount from said reference plane.

[0021] [8] The physical quantity measurement system according to [6], wherein said distance measuring device comprises two or more spot laser rangefinders, measures displacements at two or more points in the width direction of said strip-shaped object with said two or more spot laser rangefinders such that said measurement point on said strip-shaped object is interposed between the points, and acquires said displacement amount and said inclination amount from said reference plane.

[0022] [9] further comprising a driving device that causes said measurement device to scan in the width direction of said strip-shaped object, The physical quantity measurement system according to any one of [6] to [8], wherein while causing said measurement device to scan in the width direction of said strip-shaped object by means of said driving device such that said physical quantity is measured by said measurement device at a plurality of said measurement points provided in the width direction of said strip-shaped object, said displacement amount and said inclination amount are calculated at the plurality of measurement points by said arithmetic device, and a correction signal for correcting the position and angle of said measurement device is output.

[0023]

[10] The physical quantity measurement system according to any one of [6] to [8], wherein said measurement device comprises: means for acquiring the radiant light amount at said measurement point of said strip-shaped object; a regular reflection light source that irradiates light onto the surface of said strip-shaped object under regular reflection conditions; and a diffuse reflection light source that irradiates light onto the surface of said strip-shaped object under diffuse reflection conditions; wherein using said means for acquiring the radiant light amount, a regular reflection light amount obtained when light is irradiated onto the surface of said strip-shaped object from said regular reflection light source under regular reflection conditions and a diffuse reflection light amount obtained when light is irradiated onto the surface of said strip-shaped object from said diffuse reflection light source under diffuse reflection conditions are acquired, the relationship between the emissivity, regular reflectance and diffuse reflectance of the surface of said strip-shaped object is modeled, and the emissivity at said measurement point of said strip-shaped object is calculated using said model, said regular reflection light amount and said diffuse light amount. Effects of the Invention

[0024] According to the present invention, the displacement and inclination of the measurement points of the target strip-shaped object are measured, and the position and angle of the measuring device (sensor) are corrected from the displacement and inclination. Therefore, even if the strip-shaped object undergoes shape changes such as warping or fluttering, measurement errors of physical quantities can be reduced.

[0025] In particular, strip-shaped objects that are not wrapped around a roll often experience warping in the width direction, and the amount of displacement and tilt variation are large at both ends in the width direction. Therefore, the present invention is highly effective when performing multi-point measurements in the width direction, including the edges.

[0026] Furthermore, the shape data obtained by this invention, such as the displacement and inclination of the strip-shaped object, includes information on the wear status of the rolls, the soundness of the equipment, and even the mechanical properties of the product material. By comparing this data with past data, it is possible to detect abnormalities related to equipment soundness and product quality. [Brief explanation of the drawing]

[0027] [Figure 1] This is a plan view showing a first example of a physical quantity measurement system for implementing a physical quantity measurement method according to the first embodiment of the present invention. [Figure 2] This is a flowchart showing a method for measuring physical quantities according to the first embodiment of the present invention. [Figure 3] This is a plan view showing a second example of a physical quantity measurement system for implementing a physical quantity measurement method according to the first embodiment of the present invention. [Figure 4] This is a plan view showing an example of a physical quantity measurement system for implementing a physical quantity measurement method according to a second embodiment of the present invention. [Figure 5] These are a plan view and a side view showing a part of the physical quantity measurement system used in the example. [Figure 6] This diagram shows the specular reflection conditions for both point and line light sources. [Figure 7] This figure shows an example of the application of the temperature measuring device described in Patent Document 1 to a production line. [Modes for carrying out the invention]

[0028] Embodiments of the present invention will be described below with reference to the attached drawings. <Modeling> In the embodiments of the present invention, it is assumed that the measured value of the measuring device (sensor) is affected by the displacement and tilt amounts. Furthermore, it is assumed that the output value of this measuring device (sensor) changes when the positional relationship with the target strip-shaped object changes, and that the output value when these positional relationships do not change is the measured value without disturbance. That is, it is assumed that the true measured value T0 is obtained when the reference value x0 for the displacement and the reference value θ0 for the tilt amount are at the same value.

[0029] <First Embodiment> First, a first embodiment of the present invention will be described. In the first embodiment, a case will be described in which a measuring device (sensor) is used to measure the central point of a strip-shaped object being transported.

[0030] [First example of a physical quantity measurement system used in the first embodiment] Figure 1 is a plan view showing a first example of a physical quantity measurement system for carrying out a physical quantity measurement method according to the first embodiment of the present invention.

[0031] The physical quantity measurement system 20 in Figure 1 comprises a measuring device (sensor) 21, a two-dimensional laser distance meter 22, and a calculation device 23.

[0032] The measuring device (sensor) 21 measures physical quantities of the strip-shaped object S, and in this embodiment, it measures physical quantities at the measurement point P in the center of the strip-shaped object S while it is being transported. The measuring device 21 may be, for example, one that acquires the amount of radiant light from the strip-shaped object S. Furthermore, the measuring device 21 may also include, as shown in Patent Document 1 (see Figure 7), means for acquiring the amount of radiant light at the measurement point P of the strip-shaped object S, for example, a radiation thermometer, a specular reflection light source that irradiates the surface of the strip-shaped object S with light under specular reflection conditions, and a diffuse reflection light source that irradiates the surface of the strip-shaped object S with light under diffuse reflection conditions. The measuring device 21 may use the means for acquiring the amount of radiant light (for example, a radiation thermometer) to acquire the amount of specularly reflected light when the surface of the strip-shaped object S is irradiated with light under specular reflection conditions from the specular reflection light source, and the amount of diffusely reflected light when the surface of the strip-shaped object S is irradiated with light under diffuse reflection conditions from the diffuse reflection light source. The relationship between the emissivity of the surface of the strip-shaped object S, the specular reflectivity, and the diffuse reflectivity is then modeled, and the emissivity of the measurement point of the strip-shaped object S is calculated using this model, the amount of specularly reflected light, and the amount of diffusely reflected light.

[0033] The two-dimensional laser distance meter 22 is a device that divides a linear region in the width direction of a strip-shaped object S to be measured into equal parts and measures the distance of each point from the distance meter body. It functions as a distance measuring device that measures the distance around the measurement point P of the measuring device (sensor) 21 on the strip-shaped object S. The two-dimensional laser distance meter 22 can measure the distance of the strip-shaped object S in two dimensions and can measure the shape profile around the measurement point P of the strip-shaped object S. The two-dimensional laser distance meter 22 may be provided integrally with the measuring device (sensor) 21.

[0034] The calculation unit 23 acquires measurement data from the two-dimensional laser distance meter 22 and calculates the displacement Δx and inclination Δθ from the reference plane around the measurement point of the measuring device (sensor) 21 on the strip-shaped object S from the measured shape profile. Based on these calculated values, it outputs a correction signal to the measuring device (sensor) 21 to correct its position and angle. Based on this correction signal, the position and angle of the measuring device (sensor) 21 are corrected. The reference plane is the starting point for determining the position of the object to be measured. For example, when the strip-shaped object S is transported vertically as shown in Figure 7, a string can be hung between the transport rolls before and after the measurement point (at both ends) of the transport rolls arranged at a constant pitch, and tension can be applied to that surface, which can be used as the reference plane.

[0035] [Physical quantity measurement method of the first embodiment using the physical quantity measurement system of the first example] Next, a physical quantity measurement method according to the first embodiment, which is performed by the physical quantity measurement system configured as described above, will be explained. Figure 2 is a flowchart showing such a physical quantity measurement method.

[0036] This physical quantity measurement method involves continuously transporting a strip-shaped object S using the physical quantity measurement system 20, while measuring a physical quantity at a single central point of the strip-shaped object S using a measuring device (sensor) 21. The method includes the steps of: determining the displacement Δx and inclination Δθ from a reference plane around the measurement point P of the strip-shaped object S (step ST1); and correcting the position and angle of the measuring device (sensor) based on the determined displacement Δx and inclination Δθ (step ST2). Steps ST1 and ST2 are repeated when measuring physical quantities. The details are explained below.

[0037] Step ST1 Since the strip-shaped object S is being transported and the measurement point P is not a roll-wound section, the displacement Δx and tilt Δθ are constantly changing. Therefore, if the measured values ​​from the measuring device (sensor) are used as is, the displacement Δx and tilt Δθ will act as disturbances, causing the measured value T to change and preventing the acquisition of accurate measured values. To eliminate these disturbances, in step ST1, the displacement Δx and tilt Δθ from the reference plane around the measurement point P of the strip-shaped object S are first determined.

[0038] In the physical quantity measurement system 20 shown in Figure 1, in step ST1, first, data from the two-dimensional laser distance meter 22 is transmitted to the computing device 23. Then, the computing device 23 calculates the displacement Δx and inclination Δθ of the strip-shaped object S from the reference plane around the measurement point P, based on the measurement results from the two-dimensional laser distance meter 22.

[0039] An example of the calculation method in this case is shown. The measurement positions of the two-dimensional laser distance meter 22 are x1...x k ...x K The measurement position of the laser distance meter is set to x such that the target measurement point P is at the same position in the width direction. k0 If the interval between each measurement position is Δd, the reference value for displacement is x0, and the reference value for inclination is θ0, then the measurement position x k0 The displacement Δx and the inclination Δθ in this case can be calculated using the following equations (1) and (2).

number

[0040] Δθ can be calculated from two adjacent points, or it can be calculated by fitting a curve to the profile and performing differentiation. Also, since the output value of the laser rangefinder 22 may be degraded due to noise or loss if left unprocessed, the displacement Δx and slope Δθ may be calculated after removing noise using a frequency filter such as a low-pass filter, a median filter, or polynomial approximation.

[0041] Furthermore, it is desirable that the two-dimensional laser distance meter 22 be installed with high precision so that each measurement point outputs a reference value x0 for displacement when measuring with a strip-shaped object surface that does not fluctuate in displacement Δx, tilt Δθ, etc. as the reference surface. However, due to issues such as installation conditions and precision, it is possible that the meter may be installed with a deviation in tilt or position from the reference surface. In this case, a calibration plate with high surface accuracy is installed at the position through which the reference strip-shaped object passes, and this is used as the reference surface. By measuring with the two-dimensional laser distance meter, the output of each point at that time is recorded as an offset, and the deviation in tilt or position from the reference surface can be corrected by subtracting the difference each time a measurement is taken.

[0042] Furthermore, if the position of the measurement point of the two-dimensional laser distance meter 22 and the position of the measurement point of the target physical quantity are to be made identical, the laser irradiation from the two-dimensional laser distance meter 22 itself may affect the target measurement and become a source of error. In addition, the physical arrangement of the target measuring device (sensor) 21 and the two-dimensional laser distance meter 22 may interfere with each other, making installation impossible. In such cases, interference may be avoided by making the longitudinal positions of the measurement point of the two-dimensional laser distance meter and the measurement point P of the target physical quantity on the strip-shaped object S different.

[0043] • Step ST2 In step ST2, the position and angle of the measuring device (sensor) 21, which is the target of correction, are corrected using the displacement amount Δx and tilt amount Δθ from the reference plane obtained in step ST1. Specifically, with respect to the reference value x0 of the displacement amount, the position of the measuring device (sensor) 21 is corrected so that the displacement amount Δx becomes small, preferably so that the displacement amount Δx is eliminated. With respect to the reference value θ0 of the tilt amount, the angle of the measuring device (sensor) 21 is corrected so that the tilt amount Δθ becomes small, preferably so that the tilt amount Δθ is eliminated. Specifically, the calculation device 23 outputs a correction signal based on the displacement amount Δx and tilt amount Δθ calculated by the calculation device 23, and corrects the position and angle of the measuring device (sensor) 21.

[0044] [Second example of a physical quantity measurement system used in the first embodiment] In the first example of the physical quantity measurement system 20 described above, the displacement Δx and tilt Δθ were determined based on the distance measured by the two-dimensional laser distance meter 22. However, as shown in Figure 3, instead of the two-dimensional laser distance meter 22, spot laser distance meters 24a and 24b may be placed on either side of the physical quantity measurement point P, and the displacement Δx and tilt Δθ may be determined based on the distance measured by them. Figure 3 is a plan view showing a second example of such a physical quantity measurement system in which spot laser distance meters 24a and 24b are placed on either side of the measurement point P in the width direction.

[0045] The physical quantity measurement system 20' in Figure 3 is configured similarly to the physical quantity measurement system 20 in Figure 1, except that instead of the two-dimensional laser distance meter 22, spot laser distance meters 24a and 24b are installed on either side of the measurement point P in the width direction as distance measuring devices.

[0046] [Physical quantity measurement method of the first embodiment using the physical quantity measurement system of the second example] Similarly, in the physical quantity measurement system 20' shown in Figure 3, the displacement Δx and tilt Δθ from the reference plane around the measurement point P in the strip-shaped object S are determined (step ST1), and the position and angle of the measuring device (sensor) 21 are corrected from the displacement Δx and tilt Δθ from the reference plane obtained in step ST1 (step ST2). The only difference from the physical quantity measurement system 20 in Figure 1 is that spot laser distance meters 24a and 24b are used to determine the displacement Δx and tilt Δθ.

[0047] In the physical quantity measurement system 20' shown in Figure 3, the displacement at two points in the width direction is measured using two spot laser distance meters 24a and 24b to calculate the displacement Δx and tilt Δθ. It is preferable that the two spot laser distance meters 24a and 24b are positioned such that the laser irradiation points on the strip-shaped object S are equidistant from the measurement point P, but this is not necessarily required. In this case, the displacement Δx and tilt Δθ are calculated by setting the distance from the measurement point P to the irradiation point of the left spot laser distance meter 24a as a[mm], the distance to the irradiation point of the right spot laser distance meter 24b as b[mm], and the output of each laser distance meter as x. A, x B Therefore, it can be calculated using the following equations (3) and (4).

number

[0048] In Figure 3, the displacement Δx and tilt Δθ were calculated by measuring the distance between two points in the width direction of the strip-shaped object S using two spot laser rangefinders. However, it is also possible to use three or more spot laser rangefinders to measure the distance between three or more points and calculate the displacement Δx and tilt Δθ.

[0049] [Effects of the first embodiment] According to the first embodiment, the displacement Δx and inclination Δθ from the reference plane around the measurement point P of the strip-shaped object S are determined, and the position and angle of the measuring device (sensor) 21 are corrected from the obtained displacement Δx and inclination Δθ from the reference plane, making it possible to obtain physical quantity values ​​equivalent to those obtained when the strip-shaped object S is measured at the position of the reference plane. For this reason, even if the strip-shaped object has shape variations such as warping or fluttering, the physical quantities of the strip-shaped object can be measured with high accuracy.

[0050] Furthermore, the shape data of the strip-shaped object obtained in this way includes information on the wear status of the rolls, the soundness of the equipment, and even the mechanical properties of the product material. By comparing this data with past data, it is possible to detect abnormalities related to equipment soundness and product quality.

[0051] <Second Embodiment> In the second embodiment, instead of measuring a single point in the center of the strip-shaped object in the width direction, multiple points spread out in the width direction are measured. [An example of a physical quantity measurement system used in the second embodiment] Figure 4 is a plan view showing an example of a physical quantity measurement system for implementing the physical quantity measurement method according to the second embodiment of the present invention.

[0052] The physical quantity measurement system 30 shown in Figure 4 comprises a measuring device (sensor) 31, a two-dimensional laser distance meter 32, a drive device 33, and a calculation device 37.

[0053] The measuring device (sensor) 31, like the measuring device (sensor) 21 in Figure 1, measures the physical quantities of the strip-shaped object S, and measures the physical quantities of the strip-shaped object S while it is being transported. The two-dimensional laser distance meter 32 is configured in the same way as the two-dimensional laser distance meter 22 in Figure 1. The two-dimensional laser distance meter 32 may be provided integrally with the measuring device (sensor) 31. In the second embodiment, there is a drive device 33 that drives the measuring device (sensor) 31 in the width direction of the strip-shaped object S. In the example in Figure 4, the drive device 33 has a slider 34 on which the measuring device (sensor) 31 is mounted, a guide rail 35 that guides the slider 34, and a drive unit 36 ​​that scans the slider 34 along the guide rail 35, and is configured as a linear guide actuator. As a result, the measuring device (sensor) 31 can measure the physical quantities of the strip-shaped object S at multiple measurement points that spread out in the width direction, rather than just one point in the center of the width direction of the strip-shaped object S, and a distribution of the physical quantities in the width direction of the strip-shaped object S can be obtained. Furthermore, if the two-dimensional laser distance meter 32 is integrated with the measuring device (sensor) 31, it is possible to scan them together as a single unit.

[0054] The arithmetic unit 37 is configured similarly to the arithmetic unit 23 in Figure 1. Specifically, it acquires measurement data from the two-dimensional laser distance meter 32, calculates the displacement Δx and inclination Δθ from the reference plane around the measurement point of the measuring device (sensor) 31 on the strip-shaped object S from the measured shape profile, and outputs a correction signal to the measuring device (sensor) 31 to correct its position and angle based on these calculated values. The position and angle of the measuring device (sensor) 31 are corrected based on this correction signal.

[0055] In the above-described apparatus, a two-dimensional laser distance meter was used to measure the distance to the strip-shaped object S. However, similar to the first embodiment, two or more spot laser distance meters can be used to scan the measuring device (sensor) 31 and correspond to multiple measurement points.

[0056] [Method for measuring physical quantities according to the second embodiment] In this embodiment, the physical quantities of a strip-shaped object S are measured at multiple measurement points P that extend in the width direction of the strip-shaped object S, and the physical quantities at each measurement point are measured continuously. At each measurement point, similar to the first embodiment, the steps of determining the displacement Δx and inclination Δθ from a reference plane around the measurement point (step ST1) and correcting the position and angle of the measuring device (sensor) from the displacement Δx and inclination Δθ from the reference plane obtained in step ST1 (step ST2) are performed. Steps ST1 and ST2 are then repeated.

[0057] In the second embodiment, the two-dimensional laser distance meter is measured at both ends (measurement position x1 and measurement position x K It is desirable that the entire width of the target strip-shaped object always exists between ). Under these conditions, the vicinity of the target measurement point is x1...x K If one of these exists, it becomes possible to determine the displacement Δx and inclination Δθ around each measurement point when scanning and taking measurements.

[0058] Furthermore, the measurement position when the measuring device (sensor) 31 is scanned may be derived from the displacement amount by installing an encoder on the drive unit. In addition, for the widthwise region of the strip-shaped object S to be measured, the position of the edge of the strip-shaped object S is automatically calculated from the shape profile of the two-dimensional laser distance meter 32, and by scanning the measurement point back and forth between both edges of the strip-shaped object S, it becomes possible to measure only the region of the strip-shaped object S, and furthermore, the position on the strip-shaped object S at each measurement point can be measured without being affected by the meandering of the strip-shaped object S. The shape profile described here is obtained by linking the distances of each point on a linear measurement position and treating it as one-dimensional vector information.

[0059] Furthermore, when the two-dimensional laser distance meter 32 is scanned integrally with the measuring device (sensor) 31, the measurement position is calculated from the encoder of the drive unit, and by combining this with the measurement value of the two-dimensional laser distance meter 32, the edge of the strip-shaped object can be detected. In this case, if the laser irradiation light does not affect the intended measurement, the displacement amount Δx and tilt amount Δθ at the same position as the measurement point on the strip-shaped object may be measured, and more accurate measurement values ​​for correction can be obtained.

[0060] Furthermore, even when using two or more spot laser distance meters instead of the two-dimensional laser distance meter described above, it is possible to similarly scan the measuring device (sensor) 31 and perform the steps of determining the displacement Δx and tilt Δθ from the reference plane around each measurement point (step ST1), and correcting the position and angle of the measuring device (sensor) from the displacement Δx and tilt Δθ obtained in step ST1 (step ST2).

[0061] In this embodiment as well, similar to the first embodiment, it is possible to obtain the effect of being able to accurately measure the physical quantities of a strip-shaped object even if the strip-shaped object is subject to shape variations such as warping or fluttering. [Examples]

[0062] Next, referring to Figure 5, an embodiment of the present invention will be described using the measurement of the temperature of a hot-dip galvanized steel sheet as a strip-shaped object as an example.

[0063] The method for measuring the temperature of a hot-dip galvanized steel sheet described in Patent Document 1 involves pre-modeling the relationship between two types of reflectivity, specular and diffuse, and radiance. This is achieved by acquiring these two types of reflectivity from the steel sheet at the exit of the alloying IH (induction heating) device using a specular and diffuse optical system, and then estimating the emissivity. This method accurately measures the temperature even with respect to fluctuations in the target's emissivity. In this case, correctly measuring specular and diffuse reflectivity is crucial for the accuracy of the emissivity estimation. However, these reflectivity values ​​are highly dependent on the displacement Δx and tilt Δθ of the measurement point on the sheet surface. Therefore, changes in shape due to warping or fluttering of the steel sheet cause changes in reflectivity even under the same surface conditions. These changes result in errors in reflectivity, which in turn cause errors in the estimated emissivity, ultimately leading to temperature measurement errors.

[0064] Therefore, in this embodiment, similar to the technology of Patent Document 1 shown in Figure 7, a temperature measuring device equipped with a radiation thermometer, a specular reflection light source, and a diffuse reflection light source was installed on the entrance side of the tropical depression. Then, as shown in Figures 5(a) and (b), two spot laser distance meters 44a and 44b were installed at positions far apart from the measurement point of the radiation thermometer 41, and so as not to interfere with the radiation thermometer 41, and the physical quantity measurement method of the present invention was implemented. However, the specular reflection light source and the diffuse reflection light source are not shown in Figures 5(a) and (b). Note that the number of spot laser distance meters can be two or more, and a two-dimensional laser distance meter may be used instead of a spot laser distance meter.

[0065] Specifically, the procedure involved two steps: (Step ST1) determining the displacement Δx and inclination Δθ from a reference plane around the measurement point of a strip-shaped object, a hot-dip galvanized steel sheet S; and (Step ST2) correcting the position and angle of the radiation thermometer based on the determined displacement Δx and inclination Δθ.

[0066] In step ST1, where displacement Δx and tilt Δθ are determined, the reference value x0 for displacement was set to 300 mm, and the reference value θ0 for tilt was set to 0 degrees. From the output values ​​of the laser rangefinder obtained at the same time as the actual current position, the displacement Δx was calculated to be 15 mm and the tilt Δθ to be 1 degree.

[0067] In step ST2, which corrects the position and angle of the radiation thermometer 41, the position and angle of the radiation thermometer were corrected using the displacement Δx and tilt Δθ obtained in step ST1. Specifically, the displacement Δx: 15 mm and tilt Δθ: 1 degree calculated in step ST1 were corrected to the current position, resulting in a corrected position of 285 mm and a corrected angle of 1 degree. This allowed the measurement to be considered under the same conditions as if it were measured at the reference surface of the hot-dip galvanized steel sheet, enabling accurate calculation of specular reflectance luminance without being affected by the displacement Δx and tilt Δθ, and allowing for accurate temperature measurement even when the shape of the hot-dip galvanized steel sheet S, the object of temperature measurement, changed.

[0068] Regarding specular reflection, within the range of the assumed maximum displacement Δx and maximum tilt Δθ, the light source can be selected and installed in such a way that the light-emitting surface of the light source is always in the specular reflection direction under all conditions, thereby ensuring that a constant amount of reflected light is always obtained regardless of changes in displacement Δx and tilt Δθ. For example, as shown in Figure 6(a), even in cases where the specular reflection condition is not met due to the tilt of the steel plate when the light source is a point light source, as shown in Figure 6(b), by using a line light source that is elongated in the direction of the assumed tilt, and further by making the amount of light emitted and the directivity at each position of the light-emitting surface uniform, an optical system that stably achieves specular reflection conditions even when the position and tilt of the target steel plate surface change can be realized.

[0069] In the above embodiment, an example was shown in which the present invention was applied to a temperature measurement method using reflectivity during the alloying process of hot-dip galvanized steel sheets. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to any measurement where the displacement or tilt of the target strip-shaped object causes disturbances in the measured value, and similar effects can be obtained. [Explanation of Symbols]

[0070] 20, 20', 30 Physical Quantity Measurement System 21, 31 Measuring devices (sensors) 22, 32 Two-dimensional laser distance meter 23, 37 Arithmetic device 24a, 24b, 44a, 44b Spot Laser Rangefinder 41 Radiation thermometer

Claims

1. A method for measuring physical quantities of a strip-shaped object, comprising continuously transporting the strip-shaped object and acquiring the amount of radiant light from the strip-shaped object using a measuring device, The first step is to determine the amount of displacement and inclination from the reference plane around the measurement point of the strip-shaped object, A second step involves correcting the position and angle of the measuring device based on the obtained displacement and tilt amounts, A method for measuring physical quantities, comprising the characteristics of a physical quantity.

2. The first step is to obtain the amount of displacement and the amount of inclination from the reference plane by measuring the shape profile of the surface of the strip-shaped object using a two-dimensional laser distance meter, as described in claim 1.

3. The first step is to measure the displacement of two or more points in the width direction of the strip-shaped object using two or more spot laser distance meters so that the measurement points of the strip-shaped object are between them, and to obtain the amount of displacement and the amount of inclination from the reference plane, as described in claim 1.

4. The method for measuring a physical quantity according to any one of claims 1 to 3, wherein the measurement points are multiple in the width direction to obtain the distribution of the physical quantity in the width direction of the strip-shaped object, and the first step and the second step are performed for each of the multiple measurement points while scanning the measurement device in the width direction of the strip-shaped object.

5. The measurement device comprises means for acquiring the amount of radiant light at the measurement point of the strip-shaped object; a specular reflectance light source for irradiating the surface of the strip-shaped object under specular reflectance conditions; and a diffuse reflectance light source for irradiating the surface of the strip-shaped object under diffuse reflectance conditions, wherein the means for acquiring the amount of radiant light acquires the amount of specular reflected light when the surface of the strip-shaped object is irradiated under specular reflectance conditions from the specular reflectance light source and the amount of diffuse reflected light when the surface of the strip-shaped object is irradiated under diffuse reflectance conditions from the diffuse reflectance light source, thereby modeling the relationship between the emissivity of the surface of the strip-shaped object and the specular reflectance and diffuse reflectance, and using the model, the amount of specular reflected light, and the amount of diffuse reflected light to calculate the emissivity of the measurement point of the strip-shaped object, as described in any one of claims 1 to 3.

6. A physical quantity measurement system that continuously transports a strip-shaped object and acquires the amount of radiant light from the strip-shaped object to measure the physical quantities of the strip-shaped object, A measuring device that acquires the amount of radiant light from the aforementioned strip-shaped object and measures the physical quantities of the aforementioned strip-shaped object, A distance measuring device for measuring the distance around the measurement point of the aforementioned strip-shaped object, A calculation device that calculates the displacement and inclination of the strip-shaped object from a reference plane around the measurement point based on the measurement values ​​from the distance measuring device, and outputs a correction signal to correct the position and angle of the measuring device based on the calculated displacement and inclination, A physical quantity measurement system having the following features.

7. The physical quantity measurement system according to claim 6, wherein the distance measuring device has a two-dimensional laser distance meter, and the two-dimensional laser distance meter measures the shape profile of the surface of the strip-shaped object and obtains the amount of displacement and the amount of inclination from the reference plane.

8. The physical quantity measurement system according to claim 6, wherein the distance measuring device has two or more spot laser distance meters, and measures the displacement of two or more points in the width direction of the strip-shaped object with the measurement points of the strip-shaped object between the two or more spot laser distance meters, and obtains the amount of displacement and the amount of inclination from the reference plane.

9. The measuring device further comprises a drive device that scans the strip-shaped object in the width direction, A physical quantity measurement system according to any one of claims 6 to 8, wherein the driving device scans the measuring device in the width direction of the strip-shaped object with the driving device so that the physical quantity is measured by the measuring device at a plurality of measurement points in the width direction of the strip-shaped object, and the calculation device calculates the displacement amount and the inclination amount at the plurality of measurement points and outputs a correction signal to correct the position and angle of the measuring device.

10. The measurement device comprises means for acquiring the amount of radiant light at the measurement point of the strip-shaped object; a specular reflectance light source for irradiating the surface of the strip-shaped object under specular reflectance conditions; and a diffuse reflectance light source for irradiating the surface of the strip-shaped object under diffuse reflectance conditions, wherein the means for acquiring the amount of radiant light acquires the amount of specular reflected light when the surface of the strip-shaped object is irradiated under specular reflectance conditions from the specular reflectance light source and the amount of diffuse reflected light when the surface of the strip-shaped object is irradiated under diffuse reflectance conditions from the diffuse reflectance light source, thereby modeling the relationship between the emissivity of the surface of the strip-shaped object and the specular reflectance and diffuse reflectance, and using the model, the amount of specular reflected light, and the amount of diffuse reflected light to calculate the emissivity of the measurement point of the strip-shaped object, as described in any one of claims 6 to 8.

Images